A zipper assembly is a closure device commonly used in daily life, and it is composed of two chains and a slider. When the slider slips along the two chains towards one direction, the two chains will be dosed together, and when the slider slips towards the opposite direction, the two chains will be separated, thus forming a passable opening between the two chains.
Since the opening and closing of the zipper assembly is very convenient, it has now been widely used in fresh-keeping bags. Fresh-keeping bags are generally used for holding food. Some food itself contains moisture, and if the moisture (water) outflows from the fresh-keeping bag, it will pollute the refrigerator or other food. In order to prevent this situation from happening, the bag body of most existing fresh-keeping bags is made of plastic material with good waterproof performance, which can however only prevent the moisture from flowing out from the bag body, and cannot prevent the moisture from flowing out the opening. In the existing zipper assembly, in order to make the slider open or dose the zipper, an opening tongue extends generally between the non-toothed hooks on the two chains. However, with such an arrangement, complete sealing fans to be achieved between the opening tongue and the non-toothed hooks, and moisture will flow out from the gap between the opening tongue and non-toothed hooks. Therefore, such zipper assembly does not have waterproof ability, and cannot prevent the moisture from flowing out the opening.